Controlled drop dispensing tip

ABSTRACT

A controlled drop dispensing tip includes a body suitable for attachment to a dispensing bottle and a nozzle having a lumen therethrough for flow of liquid formulation. An orifice is provided in the nozzle which is in fluid communication with the lumen therethrough for formulation of droplets. The nozzle is formed from a material enabling uniform droplet dispensment of the liquid formulation independent of downward angular orientation of the tip.

The present invention is generally related to a control drop dispensingsystem and is more particularly directed to such a system including adispensing tip enabling uniform droplet dispensment.

Applicators or systems for the delivery or instillation of the liquidformulations into an eye by a user have long been known.

Generally, bottles or vials, which contain eye drop formulations, areflexible and have walls sufficiently thin to enable squeezing of thebottle through a nozzle and dispensing orifice.

In use, the user suspends the bottle over an eye to be treated in aninverted or semi-inverted position in order to direct the nozzle towardthe eye. The formulation is expelled as the user manually squeezes thewall of the bottle body or a bottom of the bottle. This pressuredifferential within the bottle drives out a quantity of formulationwhich exits the vial or bottle via the nozzle orifice as a droplet anddescends through gravity into the eye positioned below the nozzle.

While this procedure appears to be straightforward, it often cannot beperformed satisfactorily with small volume bottles in order to dispenseuniform drops. In addition to handling problems associated with oversqueezing or unintentional squeezing of the bottle, the angle of thebottle and nozzle with regard to the eye is significant in determiningthe droplet size produced.

The droplet size is important in that the dose prescribed to the patientmust often be accurately adhered to. If the quantity which iseffectively delivered is insufficient, the treatment may not beefficient. On the other hand, if the quantity delivered is too large thesurplus in certain cases may cause side effects.

Accordingly, it is important to be able to administer an exact dose ofthe formulation required and the present invention provides for acontrolled drop dispensing tip and system enabling uniform dropletdispensment of the liquid formulation independent of downward angularorientation of the tip.

SUMMARY OF THE INVENTION

A controlled drop dispensing tip in accordance with the presentinvention generally includes a body suitable for attachment to adispensing bottle and a nozzle having a lumen therethrough for flow ofliquid formulation and an orifice in fluid communication with the lumenfor the formation of droplets.

A nozzle is formed from a material which enables uniform dropletdispensement of the liquid formulation which is independent of downwardangular orientation of the tip.

A system in accordance with the present invention includes a bottle anda liquid formulation disposed in the bottle in combination with thehereinabove described dispensing tip.

More particularly, the tip in accordance with the present invention maybe a nanocomposite including a polymer and a nanofiller. The polymer maybe low-density polyethylene and the nanofiller may be present in anamount of between about 9% and about 11% by weight, preferably about 10%by weight.

Thus, the present invention provides for a nozzle which is formed from amaterial comprising a nanocomposite in an amount enabling uniformdroplet size dispensement of liquid formulation which is independent ofthe downward angular orientation of the tip. Preferably, a liquidformulation is Alphagan® or Refresh Liquigel®.

Accordingly, a method for controlling dispensed droplet size includesproviding a squeezable bottle, disposing a liquid formulation within thebottle and attaching a dispensing tip to the bottle, the tip beingformed from a material enabling uniform droplet dispersement of saidliquid formulation independent of downward angular orientation of thetip. Subsequently, the bottle is squeezed with the tip oriented in anydownward direction.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be more clearly understood with reference tothe following detailed description in conjunction with the appendeddrawings, of which:

FIG. 1 is an illustration of a prior art bottle system indicating avariance in droplet formation which is dependent upon the downwardangular orientation of the tip;

FIG. 2 is an illustration of a tip and bottle system in accordance withthe present invention similar to the illustration shown in FIG. 1indicating uniform drop dispensement despite angular downwardorientation of the tip; and

FIG. 3 is a cross-section of a nozzle tip suitable for use in thepresent invention.

DETAILED DESCRIPTION

With reference to FIG. 1, there is shown a conventional prior art bottle10 having a nozzle 12 for the dispensement of droplets 14, 16.

As illustrated, the droplet size is dependent upon the angularorientation indicated by the letter A of the nozzle 12 to an ordinance20, as hereinafter described. This variance in droplet size may vary upto 50% or more. For example, a prior art bottle may dispense a dropletsize of about 12 microliters at 90%, whereas at an angle A of 45% thesame prior art bottle may dispense a droplet size of about 26microliters.

This variation in droplet size is also dependent upon the droplet size.For example, droplet sizes between 40 and 50 microliters are not asdependent upon orientation of delivery as are droplets of smaller size.

The present invention overcomes this effect through the utilization ofnanocomposites.

With reference to FIG. 2 there is shown a system 30 in accordance withthe present invention which includes a bottle 32, a liquid formulation34 disposed within the bottle 32 and a tip 36 having a body 38 suitablefor attachment to the bottle 32 in a conventional manner, see also FIG.3.

The tip 36 includes a nozzle 42 having a lumen 44 and an orifice 48 influid communication with the formulation 34 for the dispensement ofdroplets 50 of uniform size independent of a downward angularorientation A of the tip 36.

Preferably, the bottle 34 is formed from a low-density polyethylene anddroplet size is unexpectedly found to be uniform despite a downwardangular orientation of the tip 36 through the use of nanofillers in thelow-density polyethylene (LDPE), preferably Dupont resin 206064. Suchnanofilled LDPE material may be produced in a conventional manner suchas, for example, set forth in U.S. Pat. No. 6,602,966. This patent is tobe incorporated herewith in its entirety for the purpose of illustratingthe manufacture of a nanocomposite filled polymer useful in the presentinvention.

A variety of nanofillers for use in nanocomposites are suitable for usein the present invention. Such nanofillers include natural clays (mined,refined and treated); synthetic clays; nanostructured silicas;nanoceramics; and nanotubes (carbon based) as set forth in an articleentitled “Enhancing Medical Device Performance With NanocompositePolymers in Medical Device and Diagnostic Industry” pp. 114-123 (May2002). This article is to be incorporated herewith in its entirety forthe purpose of describing suitable nanofillers for formation of thenanocomposite in accordance with the present invention for the usewithin the nozzle 42.

Unexpectedly, it has been found that utilization of a nanofilter such asa montmorillonite clay (Merck Index [1318-93-0]) available from AldrichChemical Company, Milwaukee, Wis. in an amount of between about 9% and10% by weight, preferably about 10% enable a uniform droplet 50formation independent of downward angular orientation A of the tip 36,as shown in Table 1. Table 1 reports droplet 50 size in microliters as afunction of downward angular orientation between 45° and 90° for ananocomposite of LDPE and nanofiller between 5% and 10% compared with aconventional Teflon material.

As shown for the formulations Alphagan® and Refresh Liquigel® dropletsizes are uniform compared to droplet sizes at 45° and 90° for Teflonand lower percentages of nanofiller. This effect is not as strong withformulations such as Lumigan.

These droplets were formed utilizing the nozzle 36 shown in FIG. 3 whichfurther includes an arcuate surface of revolution 60 surrounding theorifice 48 and depending from the orifice 48. It should be appreciatedthat the nozzle 36 is shown for illustrative purposes and that othernozzles may be utilized when formed from a material having interfacialtension with the liquid formulation 34 enabling uniform dropletdispensement of liquid formulation independent of downward orientationof the tip 36. TABLE 1 Alphagan Lumigan Refresh Liquigel Nozzle Material45 Degrees 90 Degrees Overall 45 Degrees 90 Degrees Overall 45 Degrees90 Degrees Overall 10% Nanocomposite 15.8 17.9 16.9 26.4 14.7 20.6 15.417.9 16.7 8% Nanocomposite 35.1 18.7 26.9 23.9 12.8 18.4 33.2 18.2 25.75% Nanocomposite 34.5 18.8 26.7 26.5 12.1 19.3 33.7 21.4 27.6 TeflonBlend 33.0 25.9 29.5 33.3 20.6 27.0 26.3 12.0 19.2

As hereinabove summarized a method in accordance with the presentinvention includes disposing a liquid formulation such as, for example,Alphagan® or Refresh Liquigel® into a squeezable bottle and attaching adispensing tip to the bottle, the tip being molded, shaped or otherwiseformed with a material enabling uniform droplet dispersement of saidliquid formulation independent of downward angular orientation of thetip, the material comprises nanocomposites such as hereinbeforediscussed.

Uniform droplet dispersement is effected through squeezing the bottlewith the tip orientation in a downward direction, such as, for example,between 45° and 90° as illustrated by the angle A in FIG. 2.

Although there has been hereinabove described a specific controlled dropdispensing tip in accordance with the present invention for the purposeof illustrating the manner in which the invention may be used toadvantage, it should be appreciated that the invention is not limitedthereto. That is, the present invention may suitably comprise, consistof, or consist essentially of the recited elements. Further, theinvention illustratively disclosed herein suitably may be practiced inthe absence of any element which is not specifically disclosed herein.Accordingly, any and all modifications, variations or equivalentarrangements which may occur to those skilled in the art, should beconsidered to be within the scope of the present invention as defined inthe appended claims.

1. A controlled drop dispensing tip comprising: a body suitable forattachment to a dispensing bottle; and a nozzle having a lumentherethrough for flow of a liquid formulation and an orifice in fluidcommunication with said lumen for the formation of droplets, said nozzlebeing formed from a material enabling uniform droplet dispensement ofsaid liquid formulation independent of downward angular orientation ofsaid tip.
 2. The tip according to claim 1 wherein said material is apolymer.
 3. The tip according to claim 2 wherein said polymer comprisesa nanocomposite.
 4. The tip according to claim 3 wherein said polymercomprises low-density polyethylene.
 5. The tip according to claim 4wherein said nanocomposite includes a nanofiller present in an amount ofbetween about 9 and about 11% by weight.
 6. The tip according to claim 4wherein said nanocomposite includes a nanofiller present in an amount ofabout 10% by weight.
 7. A controlled drop dispensing system comprising:a bottle; a liquid formulation disposed in said bottle; a tip having abody suitable for attachment to said bottle and a nozzle formed from amaterial enabling uniform droplet dispensement of said liquidformulation independent of downward angular orientation of said tip. 8.The system according to claim 7 wherein said material is a polymer. 9.The system according to claim 8 wherein said polymer comprises ananocomposite.
 10. The system according to claim 9 wherein said polymercomprises low-density polyethylene.
 11. The system according to claim 10wherein said nanocomposite includes a nanofiller present in an about ofbetween about 9 and about 11% by weight.
 12. The system according toclaim 10 wherein said nanocomposite is present in an amount of about 10%by weight.
 13. The system according to claim 12 wherein said liquidformulation comprises Alphagan®.
 14. The system according to claim 12wherein said liquid formulation comprises Refresh Liquigel®.
 15. Acontrolled drop dispensing tip comprising: a body suitable forattachment to a dispensing bottle; and a nozzle having a lumentherethrough for flow of a liquid formulation and an orifice in fluidcommunication with said lumen for the formation of droplets, said nozzlebeing formed from a material enabling uniform droplet size dispensementof said liquid formulation independent of downward angular orientationof said tip.
 16. The tip according to claim 15 wherein said material isa polymer.
 17. The tip according to claim 16 wherein said polymercomprises a nanocomposite.
 18. The tip according to claim 17 whereinsaid polymer comprises low-density polyethylene.
 19. The tip accordingto claim 18 wherein said nanocomposite includes a nanofiller present inan amount of between about 9 and about 11% by weight.
 20. The tipaccording to claim 18 wherein said nanocomposite includes a nanofillerpresent in an amount of about 10% by weight.
 21. A method forcontrolling dispensed droplet size, said method comprising: providing asqueezable bottle; disposing a liquid formulation in the bottle;attaching a dispensing tip to the bottle, the tip being formed from amaterial enabling uniform droplet dispensement of said liquidformulation independent of downward angular orientation of the tip; andsqueezing the bottle with the tip oriented in a downward direction toproduce the uniform droplets of said liquid formulation.